Science for Saving Research findings factsheet Project 2.1

Butterflies on the brink: identifying the Australian most at risk of extinction

In brief Background Terrestrial invertebrates and their Invertebrates are declining globally in high (greater than 30%) chance of habitats are increasingly threatened both diversity and abundance, with extinction. We also identified key by human disturbances, particularly potentially serious consequences threatening processes affecting habitat loss and fragmentation, for ecosystem functioning. Many these species (chiefly inappropriate invasive species, inappropriate fire Australian butterflies are imperilled fire regimes, habitat loss and regimes and climate change. or declining but few are listed fragmentation, invasive species and Continuing declines and extinctions for protection by legislation. climate change), and the research in native terrestrial invertebrate We identified the 26 Australian and management actions needed communities are likely to negatively butterflies at most immediate risk to save them. Mapping of the 26 affect ecosystem functioning. This is of extinction within a 20-year time butterflies’ distributions revealed that because invertebrates play a central frame. We found that one most are now found only in a single role in many ecological processes, is facing a greater than 90% chance state or territory and many occupy including pollination, herbivory, the of extinction in the next 20 years narrow ranges. Increased resourcing consumption of dead plant and (and may already be extinct), and and management intervention is matter, and nutrient cycling, four species have a moderate to required to avert future extinctions. as well as providing a good source of food for other . There is urgent need to explore the causes of these declines, and the implications for ecosystems and ecosystem services. We must also put appropriate management actions in place to halt and reverse declines in the species at greatest risk of extinction. Invertebrate conservation and management has many challenges. Invertebrates are generally poorly known and under-studied, and much of their vast biodiversity remains undescribed. Resources are also limited, both in terms of scientific expertise and funds, making it difficult to assess and hence

Bulloak jewel (Hypochrysops piceatus). address their conservation needs. Image: Michael Braby

Biodiversity and Conservation Science Ento Search LEFT: Larva of the Australian fritillary ( hyperbius inconstans); its host plant is the native violet (). Image: Garry Sankowsky

Background (continued) Although there have been some recent advancements in conservation assessments for butterflies in Australia, these have typically not translated into additions to statutory lists. Just 10 butterfly species are listed for protection under the Australian Government’s EBPC Act. The Australian Government has committed to averting extinctions, and this first requires identification of the species at most immediate The Australian fritillary (Argynnis hyperbius inconstans) on risk. We worked with experts to native violet. Image: Garry Sankowski identify highly imperilled Australian butterfly species and subspecies What we did that are threatened with extinction in the near future. The project consisted primarily of Distributions – We mapped desktop research and structured the distribution of the most The experts included NESP interviews with experts. imperilled butterflies using Threatened Species Recovery Hub distribution data compiled from Identifying at risk species – researchers; amateur entomologists The Complete Field Guide to We produced a preliminary list (who carry much of the natural Butterflies of Australia. See Figure 1. history knowledge of butterflies in of Australian butterflies at high Australia); and butterfly biologists risk of extinction based on all Threats and management – from academic institutions, state available published and unpublished We identified key threats to or federal government agencies information; this included each species from the published and environmental NGOs. They information provided by butterfly literature, conservation listing included representatives from experts, including at a workshop advices, the Action Plan for every Australian state or territory. in 2019. From this we finalised Australian Butterflies, and from a list of 26 species most likely unpublished information from and Research aims to be lost to extinction within observations by species experts. 20 years. See Table 1. We classified the threats using We aimed to: the IUCN Threats Classification Extinction probabilities – Scheme. We used this information 1. identify the Australian butterflies We used structured expert to determine the number and at most immediate risk of elicitation to obtain estimates of proportion of species affected extinction in the next 20 years; extinction probability in the next by the various threat types. 2. estimate their probability of 20 years. Our approach involved extinction (in the wild) by 2040; giving participants relevant We identified relevant research information on ecology, threats and management actions for 3. map their distribution to identify and trends, then asking them to reducing risks of extinction using regions for priority research estimate probability of extinction published and unpublished sources. and management; and over the 20-year time frame of We categorised these actions using 4. identify their key threats, interest. Assessments assumed the IUCN Research Needed to inform key research and current management would and Conservation Actions management objectives continue, with no new Classification Schemes. for averting future butterfly actions implemented. extinctions. Rank Scientific name Common names EX Lower Upper Conservation status in State/ EPBC 95% CI 95% CI Territory of occurence Status 1 Argynnis hyperbius inconstans Australian fritillary, laced fritillary 0.94 0.89 0.97 QLD (EN),NSW (-) CR 2 Jalmenus eubulus Pale imperial hairstreak 0.42 0.28 0.58 QLD (VU), NSW (CR) - 3 Hypochrysops piceatus Bulloak jewel 0.37 0.24 0.53 QLD (EN) - 4 munionga larana Marrawah , alpine sedge-skipper 0.33 0.2 0.49 TAS (EN) VU 5 Jalmenus aridus Inland hairstreak 0.3 0.15 0.5 WA (P1) - 6 Ogyris sp. aff. aenone Sapphire azure (southern population) 0.28 0.16 0.44 QLD (-) - 7 Ogyris subterrestris subterrestris Arid bronze azure 0.28 0.16 0.44 VIC (Thr), SA (-) - 8 Croitana arenaria arenaria Inland grass-skipper 0.22 0.12 0.36 NT (-) - 9 Heteronympha banksii nevina Banks’ brown 0.19 0.1 0.32 VIC (-) - 10 Heteronympha cordace wilsoni Bright-eyed brown 0.18 0.1 0.3 VIC (Thr), SA (-) - 11 Ogyris subterrestris petrina Arid bronze azure 0.15 0.08 0.26 WA (CR) CR 12 Candalides noelkeri Golden-rayed blue 0.13 0.07 0.23 VIC (Thr) - 13 Antipodia chaostola leucophaea Tas. chaostola skipper, heath sand-skipper 0.11 0.06 0.19 TAS (EN) EN 14 Acrodipsas illidgei Mangrove ant-blue, Illidge’s ant blue 0.1 0.05 0.17 QLD (VU), NSW (-) - 15 Oreixenica ptunarra Ptunarra xenica, ptunarra brown 0.09 0.05 0.17 TAS (VU) EN 16 Ogyris otanes sublustris Western dark azure 0.09 0.05 0.17 WA (-) - 17 Ogyris iphis doddi Dodd’s azure, orange-tipped azure 0.07 0.03 0.14 NT (EN) - 18 Hesperilla flavescens flavescens Yellow sedge-skipper 0.07 0.03 0.14 VIC (Thr) - 19 Exometoeca nycteris Western flat 0.07 0.03 0.14 WA (-) - 20 Oreixenica latialis theddora Small alpine xenica 0.06 0.03 0.12 VIC (Thr) - 21 Ogyris halmaturia Eastern bronze azure 0.06 0.03 0.11 VIC (Thr), SA (-) - 22 Ogyris otanes otanes Small bronze azure 0.06 0.03 0.11 NSW (-), VIC (-), SA (-) - 23 Ocybadistes knightorum Black grass-dart 0.05 0.03 0.1 NSW (EN) - 24 Telicota eurychlora Southern sedge-darter 0.03 0.01 0.05 QLD (-), NSW (-), VIC (Thr) - 25 spinifera Purple copper, Bathurst copper 0.03 0.01 0.05 NSW (EN) VU 26 Hypochrysops apollo apollo Apollo jewel 0.02 0.01 0.04 QLD (VU) -

Table 1. The scientific and common names, likelihoods of extinction based on structured expert elicitation with lower/upper 95% confidence intervals, and listed conservation status in state/territory of occurrence and under EPBC Act for the 26 most imperilled Australian butterflies. (- denotes Not Listed).

Key findings

Of the 26 butterflies included in with no confirmed specimen but some are believed to be locally our assessment, only six were listed records since 2001. Another four extinct. For example, the small as threatened under Australian butterflies had a moderate to high bronze azure (Ogyris otanes otanes) federal legislation (the EPBC Act) probability of extinction (30–50%). is most likely locally extinct in New South Wales and possibly Victoria, as of February 2020, with a further We estimated that five butterflies with surviving populations confirmed two nominated. A larger number could be lost to extinction by 2040 only in South Australia, while the (20) were recognised as threatened unless management improves, and under the relevant legislation there was a high level of agreement eastern bronze azure (Ogyris for one or more of the states or about this among experts. halmaturia) is almost certainly locally territories in which they are extinct from its formerly wide range All 26 species of Australian known to occur. in western Victoria, and now persists butterfly are found nowhere else precariously at only two or three The Australian fritillary (Argynnis but Australia, and 18 are found locations in South Australia. hyperbius inconstans) is at only in a single state or territory. extremely high risk of extinction The remaining eight are known Threats within the next 20 years (likelihood historically from two or three We found that the most prevalent >90%). It may already be extinct, neighbouring states or territories, threats to the imperilled butterflies Figure 1. The Australian butterfly species and sub-species at greatest risk of extinction. * indicates a sub-species # indicates a population. Image: Threatened Species Recovery Hub

Key findings(continued) were natural system modifications, Figure 2. The number of imperilled Australian such as changes to fire regimes, butterflies affected or dams and water management by different types of impacts on the vegetative habitat threats, categorised using the IUCN Threats of the species (a threat to 21 Classification scheme. of the butterflies). The total number of species affected by each Other important threats included broad threat category is agriculture, notably the clearing provided in parentheses. Note that “Natural system and fragmenting of habitat change” includes fire associated with non-timber crops and fire suppression, and domestic livestock (affecting and weather refers to extreme weather events. 17 butterflies), and invasive species, particularly introduced grasses, European rabbits and introduced invertebrates (affecting 14 butterflies). Key findings(continued) Climate change is likely to affect almost half of the butterflies we considered (11), with increases in temperature, longer and more frequent droughts and sea level rise potentially catastrophic future threats. See Figure 2.

Need for further surveys and research All 26 butterflies are likely to benefit from further surveys, which could more precisely estimate geographic distribution, population size and density. Black grass-dart (Ocybadistes knightorum). Likewise, all 26 butterflies Image: Mick Andren would benefit from further research to assess the impacts Management actions 1. education and awareness of threatening processes, The experts estimated an average (site visits, signage, discussions especially the role of fire. probability of extinction of 18% for with private landholders and land managers); The ecological requirements of the 26 butterflies over the next 20 10 butterflies, such as habitat years. This suggests that without 2. land/water management and seral stage critical to their adequate new management (appropriate fire management, survival and interactions with actions the total number of future invasive species control); and ants, require further investigation. extinctions may be significant. 3. land/water protection (identifying and protecting sites The of six of the We found that the most important of high conservation value). butterflies requires clarification. management actions to reduce the risk of extinction were:

Implications and recommendations These findings will be of greatest be implemented to prevent their with narrow ecological requirements, practical value to decision-makers extinctions before it is too late. such as dependence on a single and funding bodies such as state While no extinctions of Australian host plant, but also generalist species and Commonwealth government butterflies have been recorded that were once very common. This agencies, conservation land officially, the pace of modern suggests that earlier undetected managers, and researchers looking extinctions is suspected to extinctions are likely, and that future to prioritise and apply research have surpassed that of vertebrates. extinctions are inevitable without and management actions for However, confirming this is rapid and targeted intervention. threatened butterflies. hampered by the lack of historical Our assessments of extinction Identifying the species at greatest data on trends in population size probability preceded the 2019–20 risk of extinction can help forewarn and geographical range size. wildfires, which are likely to have governments, conservation Nevertheless, in areas of the world severely worsened the conservation managers and the community where it has been possible to assess outlook for many of the species about which species are most how populations of butterflies are considered in our study, and also for threatened, so that emergency faring, the majority have declined, many others that were not included, care and recovery actions may including not only specialist species but now may warrant inclusion. Implications and recommendations (continued) Given that we predict that up to five assess the current conservation conservation of butterflies in Australian butterflies may become status of all butterfly species of Australia, and will remain a vital extinct in the next two decades conservation concern (not just future source of information without substantial improvements to the most imperilled). This will relevant to butterfly conservation current management regimes, we assist in enabling the coordination and management. Prohibiting recommend urgently implementing of recovery efforts for nationally the collection of listed butterfly the following research and threatened butterflies. species is likely to have adverse management actions: 4. Ensuring that state/territory effects on butterfly conservation. 1. Formal listing of highly threatened governments provide more For exceptionally rare species, but currently unlisted species as leadership in the conservation put in place measures to ensure threatened under national and management of imperilled maximum responsibility for state/territory legislation, with butterflies that are restricted in their conservation. The code recovery plans/Conservation range to their jurisdictions. of conduct in the Action Plan for Australian Butterflies is still Advices developed and recovery 5. Promoting the amateur study, relevant today and should be teams established. collection and sharing of applied widely across Australia. 2. Ensure that adequate policies are information about butterflies, in place to protect habitat critical and ensuring that it is not Only urgent action, enhanced to the survival of the species at impeded by conservation policy. policy and planning, increased greatest risk. This is the most Butterfly collecting by non- community awareness and a important action for butterfly professional lepidopterists has better resourced conservation conservation in Australia. contributed significantly to the response will prevent future 3. Updating the 2002 Action Plan knowledge of the taxonomy, extinctions in Australian butterflies. for Australian Butterflies to distribution, biology and

Cited material Braby MF. (2016). The Complete Field Guide to Butterflies of Australia, Second edn. CSIRO Publishing, Melbourne. Geyle HM., Braby MF., Andren M., Beaver EP., Bell P., Byrne C., Castles M., Douglas F., Glatz RV., Haywood B., Hendry P., Kitching RL., Lambkin TA., Meyer CE., Moore MD., Moss JT., Nally S., New TR., Palmer CM., Petrie E., Potter-Craven J., Richards K., Sanderson C., Stolarski C., Taylor GS., Williams MR., Woinarski JCZ. & Garnett ST. (2021). Butterflies on the brink: identifying the Australian butterflies () most at risk of extinction. Austral Entomology. https://doi.org/10.1111/aen.12525 Sands DPA & New TR. (2002). The Action Plan for Australian Butterflies. Environment Australia, Canberra

Further Information RIGHT: Bathurst Copper Hayley Geyle – [email protected] (Paralucia spinifera). Michael Braby – [email protected] Image: Tessa Barratt

Cite this publication as NESP Threatened Species Recovery Hub. 2021. Butterflies on the brink: identifying the Australian butterflies most at risk of extinction, Research findings factsheet.

This project is supported through funding from the Australian Government’s National Environmental Science Program.